Robot cleaners, such as robot vacuums, have been proposed to clean rooms. One issue in producing a robot cleaner is the problem of controlling the robot cleaner to clean an entire room without missing regions. This problem relates to the difficulty of accurately positioning a robot cleaner.
One robot vacuum is the Roomba™ vacuum from iRobot. The Roomba™ vacuum avoids the positioning problem by making multiple passes through a room in a somewhat random fashion. The Roomba™ vacuum starts in a spiral pattern until it contacts a wall, follows the wall for a period of time and then crisscrosses the room in straight lines. After it covers the room multiple times, the Roomba™ stops and turns itself off.